Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6578705 | Chemical Engineering Journal | 2018 | 33 Pages |
Abstract
Understanding the phase characteristic of methane hydrate in materials is of recent interest in several fields. In this study, methane hydrate dissociation conditions in nine water wetted porous materials (ZIF-8, MIL-53(Al), HKUST-1, nanoporous activated carbon, zeolite 13X, and four silica gels) with pore diameters ranging from 0.35 to 100â¯nm as well as in two nonporous quartz sands were systematically investigated. The adsorption properties of methane in some selected adsorbents were also studied. For microporous materials, our results confirmed that methane hydrate cannot form due to the size limitation for the nucleation of a methane hydrate crystal. In contrast, for mesoporous materials with a pore diameter of 6.2â¯nm or bigger, hydrate formed in their pores and significantly shifted dissociation temperatures and pressures compared to the bulk hydrate were observed. The largest temperature shift was found to be â¼6â¯K in materials possessing 6.2-nm-diameter pores, and this shift decreased to less than 1â¯K in structures having 45-nm-diameter pores. For macroporous materials with a pore diameter of 100â¯nm or for nonporous quartz systems, the influence of pore sizes on the methane hydrate phase equilibrium was found to be marginal. Furthermore, from studying the adsorption characteristic of methane in 25â¯wt% wetted MIL-53(Al), 30â¯wt% wetted HKUST-1, and 10â¯wt% wetted nanoporous activated carbon, we demonstrated that the penetration of water molecules into the pores of microporous materials was not only unable to form methane hydrate but also substantially deteriorated the gas adsorption ability. To exploit simultaneously adsorption and hydrate formation in wetted microporous materials for gas storage, both the hydrophobicity and aperture pore size of materials are critical toward the selection of promising adsorbents.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Huang Liu, Siyuan Zhan, Ping Guo, Shuanshi Fan, Senlin Zhang,